The Royals optioned Bowlan to Triple-A Omaha on Thursday.
Bowlan will head to the minors after surrendering two runs off five hits and two walks while striking out two batters in 3.1 innings during spring training. The 27-year-old righty posted a 5.24 ERA and 1.55 WHIP across 67 frames with Omaha last season, and he will likely need to show further improvement in Triple-A before the Royals bring him back to the big-league squad.